This application claims benefit of Japanese Application Nos. 2001-269303 filed on Sep. 5, 2001, 2002-143618 filed on May 17, 2002, 2002-183266 filed on Jun. 24, 2002, 2002-183267 filed on Jun. 24, 2002, the contents of which are incorporated by this reference.
1. Field of the Invention
The present invention relates to an electric bending endoscope for bending a bending portion provided in an inserting portion by moving a traction member by driving means.
2. Description of the Related Art
Conventionally, an endoscope has been widely used as an apparatus for observing and examining inside of a body cavity, tube or a gap in a construction and so on. This endoscope mainly includes an inserting portion to be inserted to a body cavity or a construction and an operating portion provided at the base end portion of the inserting portion. Some may have a bending portion provided to the inserting portion, which can be bent in the horizontal and vertical directions.
The bending portion performs a bending operation by moving back and forth a operating wire, not shown, which is a traction member inserting through the inside of the inserting portion. Thus, the distal end portion of the operating wire is fixed at the bending portion, and the base end portion is fixed at an operating wire attaching mechanism portion. The operating wire attaching mechanism portion is united with a single curving operating lever, which is an operation instructing lever provided in the operating portion. With this structure, by slantingly operating the curving operation lever, the corresponding operation wire is moved back and forth. Thus, the bending portion can be bent in a desired direction.
The endoscope having the structure in which the curving operation lever is slantingly operated to bend the bending portion as described above has advantages and disadvantages as follows: One of the advantages is that a bending operation in four directions, for example, can be performed by the single bending operation lever. On the other hand, one of the disadvantages is that the physical load on a user is too large. Since the bending operation lever is slantingly manipulated to tract a corresponding operation wire directly, the bending operation lever becomes heavier. In addition, significantly large force is required to maintain a bent condition of the bending portion.
In order to overcome the disadvantage, many endoscopes have been proposed which has a traction member operating device for reducing an amount of operating the bending operation lever and for increasing an amount of bending the bending portion.
For example, in a head bending apparatus disclosed in Japanese Examined Utility Model Registration Application Publication No. Sho 56-48241, two semicircular plates each of which is bent to a semicircular having a long recess are assembled such that the long recesses can cross at right angles. An operation lever is inserted to the crossed long recesses. In addition, shafts of both ends of both of the semicircular plates are rotatably supported by a stationary axis. A pivot is provided such that a semicircular rotation can be transmitted onto the extension of the stationary axis. The pivot is connected to a wire operation mechanism. Thus, bending operations in four directions can be performed by a single operation lever.
Furthermore, in a head bending device disclosed in the Japanese Examined Utility Model Registration Application Publication No. Sho 63-5684, two semicircular plates each of which is bent to a semicircular having a long recess are assembled such that the long recesses can cross at right angles. In the bending device in which an operating lever is inserted through the crossed long recesses, a shaft of one end portion of the semicircular plate is supported by a bearing. The other end portion is connected to multiple planetary gears engaging with an internal teeth, which is formed within an angle drum winded with an angle operation wire. Thus, an amount of the wire movement is increased.
Furthermore, in an endoscope disclosed in Japanese Examined Utility Model Registration Application Publication No. Hei 2-42246, a hydropneumatic cylinder is provided in an operation body. A piston rod of the hydropneumatic cylinder is linked to a pulley, which is rotator supported by the operation body. A banding portion is bent through an operation wire linked to the pulley so as to reduce an amount of operation force.
Furthermore, an endoscope disclosed in Japanese Unexamined Patent Application Publication No. Sho 58-65132 includes a motor for driving a distal end bending mechanism, a bending operation member provided in an operation portion for receiving operation force manually, a detecting unit for detecting an amount of operation force received by the bending operation member and a control unit for processing a signal obtained by the detection unit and for controlling driving electric power to the motor. Thus, the amount of operation force is detected so as to drive the motor.
However, the methods for bending a bending portion as disclosed in the Japanese Examined Utility Model Registration Application Publication No. Sho 56-48241, Japanese Examined Utility Model Registration Application Publication No. Sho 63-5684, Japanese Examined Utility Model Registration Application Publication No. Hei 2-42246 are complicated in the construction. Thus, there is a disadvantage that the form becomes larger. In addition, since the more an amount of moving a wire for bending the bending portion is increased, the more the amount of operation is increased. Thus, it is not practical.
In the bending method of the bending portion disclosed in the Japanese Examined Utility Model Registration Application Publication No. Sho 58-65132, an amount of operation is detected, and a motor is driven in accordance with the detected amount of operation. Thus, a control circuit is required, which complicates the structure.
In addition, when a hand holding the operating portion is frequently lifted in handling the endoscope, a load is put on an arm supporting the endoscope. Thus, it is likely that the operability is reduced with the passage of time.
On the other hand, the endoscope needs a light source for illuminating an observed subject since a diagnosed or examined subject is in a living body, a plant or the like. Therefore, a light source device is prepared as an external device of the endoscope.
When the endoscope is optical, an end surface of an image guide is located at an image forming position of an observation optical system. Then, the formed image is transmitted to the base end side of the inserting portion through the image guide. Thus, a user can observe an endoscope-observed part under magnification through an eyepiece. As a result, an endoscope apparatus can be constructed which is excellent in mobility by having a battery, such as a dry battery and a chargeable battery, as a power source of the light source device. Therefore, the use in a place into which carrying a large light source device is difficult or a place where a commercial power source cannot be obtained becomes possible. Especially, an excellent effect can be shown in an emergency.
However, when an endoscope is electronic, an image pickup element such as charge coupled device (CCD) is located at an image-forming position, and an optical image is optoelectronic-transduced to image signals. The image signals output from the image pickup element are signal-processed in a video processing device to create video signals. The video signals are output to a monitor device. Thus, an image of the endoscope-observed part is displayed on a screen to perform an observation thereof.
In other words, when an examination is performed by using the electronic endoscope, the video processing device and a monitor device are required in addition to the combination of an endoscope and an optical source device, which is a construction of the optical endoscope apparatus. Therefore, it is difficult to construct an endoscope as a mobile device.
It is an object of the present invention to provide an electric bending endoscope excellent in operability in that a desired traction member is moved by a desired amount to bend a bending portion by slantingly operating an operation instructing lever with a small amount of operation force.
It is another object of the present invention to provide an electric bending endoscope excellence in grasp and operability in that a load onto an arm of a user grasping the endoscope is reduced and a twisting operation of an inserting portion and/or a bending operation of a bending portion can be performed freely.
It is another object of the present invention to provide an electric bending endoscope excellent in workability and mobility by using a battery such as a dry battery and a chargeable battery as a power source of each of an electric bending endoscope, light source device, a video processing device and a monitor.
An electric bending endoscope having a traction-member operating device according to the present invention has traction members each of whose one end portion is fixed to and extends from a distal end portion of a long and narrow inserting portion, a pulley forming multiple peripheral recesses in which middle parts of the traction members are wound and are located in predetermined states, respectively, a motor for rotating, in a predetermined direction, the pulley in the state where the traction members are wound and are located, an arm member having a plurality of arm members to which base end portions of the traction members wound and located in the peripheral recesses of the pulley and extended therefrom are fixed, and an operation instructing lever to which the arm member is integrally fixed and having an operating portion for changing a slanting direction and a slanting amount to instruct to move a predetermined traction member from the plurality of traction members by a predetermined amount. Therefore, a load on a user is reduced, and the operability and the workability are improved.
The above and other objects, features and advantages of the invention will become more clearly understood from the following description referring to the accompanying drawings.